Stapler



FIG. 1 is a top, front, right side perspective view of a stapler showing my new design;

FIG. 2 is a right elevation thereof, the left side being a mirror image of the right side;

FIG. 3 is a front elevation thereof;

FIG. 4 is a rear elevation thereof; and

FIG. 5 is a bottom plan view thereof. 

The ornamental design for a stapler, as shown and described. 